This invention relates generally to a unique carpenter's square that is especially designed for quick measurement of roof pitch. Carpenter's squares, including those with level of spirit provided in one leg of the square, are of course well known in the art. However, no prior art Carpenter's square to my knowledge has been designed to provide a convenient tool for measuring roof pitch. Normally, the carpenter must perform calculations that can lead to errors, and that are time consuming in nature.
It is known, for example, to provide a carpenter's level (of two to four feet in length) so that one end of the level contacts the roof, and to hold the ruler or tape measurer so that the free end of the level is above the roof. The carpenter then measures the elevation of the free end of the level, but must then calculate the slope based on the inches on his tape measurer, and the length of his level to arrive at the actual roof pitch in inches per foot.
The object of the present invention is to provide a single tool or device that the carpenter can carry in his tool box, and that can be used to directly measure roof pitch in inches per foot, and incidentally in angular degrees of roof pitch as well.
In accordance with the present invention, a carpenter's square is provided with a horizontally extending leg equipped with a spirit level so as to assure that this leg of the square is held horizontal while a vertical leg of the square is slidably received in the end portion of the horizontal leg so it can be conveniently clamped by a set screw to afford an indication in inches per foot of roof slope. The horizontal leg of the square is made exactly 12 inches from the inside edge of the vertical member to the outer edge of the horizontal leg or member, and may have an overall length of 14 inches.
The vertical leg is slidably received in the end portion of the horizontal leg and may have overall length of approximately 20 inches in length so as to afford a convenient means for measuring roof pitch of relatively steep slope.